Insurance company runaround in Canada. Advice please.

My mom visited the US in December 2017 and had a fall while there. She was treated at hospital and gave them the insurance info. When she returned to Canada, she sent the claim forms to the insurance company. The claim is still not processed. I would like to know if filing a complaint to the BBB is appropriate, and if not, what else I can do to make sure that the company processes the claim and pays the bill ($4000 USD). It is stressing all of us out, especially my mom. Background info inside. The accident happened while my mom visited my sister and her partner in the US in December. The following is a timeline of our attempts to contact the insurance company. We are at our wits' end, because the insurance company will not talk directly to the hospital and (more importantly) seems almost willfully incompetent. We have spent so much time trying to deal with this but a resolution seems remote.

Just as an FYI, my mom never talked to the insurance company directly because of language barrier and hearing loss.

• December 1, 2017 - Mom had her accident. My sister's partner was at the hospital with her, and he called the insurance company from there. My mom filled out the paperwork at the hospital, referring to the insurance company.


• December 21-22 - Back in Canada, the completed claim forms were sent to the insurance company. I verified that this is within the allotted time for filing claims. My mom also got Canada Post tracking and took a screenshot of the online tracking. Unfortunately, she did not get a screenshot of the actual signature (not sure if that's helpful anyway?).


• Late February/early March, 2018 - Hospital sent an unpaid bill to my sister in the US. They also made phone calls about the unpaid bill. This is how we found out the bill was not paid yet.


• March 2 - My mother’s advisor called insurance company and was told to email the documentation. She did as advised, and received an automated reply. She received no confirmation that anything was being done on the claim.


• March 23 - Advisor called insurance company. Representative stated that still no claim was received, so they sent the forms again on March 13th. No second set of forms was ever received.


• April 13 - I called hospital to inform them that I would be following up with insurance. They told me that the bill would be going to collections if the payment was not received in a timely manner.
  I called insurance and was told that I had to send hard copies of the forms even though I stated and the representative reiterated that there were copies. She told me it would take up to four days to receive the forms in email.


• April 19 - Because I did not receive the forms after four working days, I called insurance company. The representative stated that I did not have to send the hard copies if I had soft copies. He advised that I fax the forms, but told his colleague to email the forms as well. I received them while still on the phone call.


• May 7 - I called the insurance company and confirmed they received all the necessary supporting documents to start the claim process. They said to call them in 7-10 days to confirm status, or call the hospital in that time.
  
• May 18 - Called hospital. No payment. They said they put the account on hold to wait for payment, instead of sending to collections.
  
• May 31 - Called insurance company, who said the case is still pending because it was “assigned to someone who does not work here anymore”. They said they will re-assign. I asked the representative to do that while I was on the phone with him, but he said it was through email. He said to wait 7-10 days AGAIN. I called the hospital and left a message with them.

I think that our experience in this matter is both unreasonable and unacceptable. (If not, please correct me.) I have real doubts that this will be resolved soon and want to file a complaint with the BBB--or other entity, if another is more appropriate. Do you have any advice on my next steps?

Thank you all.