non payment of account since July

I have been having a problem submitting a claim since July 2015, after receiving terrible service from your call center, with noone calling me back and waiting on the line for over 30 mins everytime trying to get through to a team leader. I have now submitted 3 written complaints, after 2 weeks of submitting the complaint I got a response saying that the resolution to my complaint was attached, the 'resolution' was that GEMS was going to look into it and I have received nothing further. I have received part payment for this account, but am waiting on the remainder to be paid. I am extremely disatisfied with the service I have recieved as it has been a waste of my time and money. I am hoping that this can be resolved before my claim becomes stale.