Lack of service!

FNB Merchant Services. I have a credit card merchant machine that I need to return to FNB, I have emailed that specific department and no-one has bothered to get hold of me. The reason that I have decided to go this root rather than continue to try and get a hold of then is that for over three months I tried to get them to come and change the name on the credit card receipts as I was using the machine for a new business however nobody did anything and now I've closed due to Covid and can ill afford to pay for the rental of a machine that is just sitting!!! Can someone please get a hold of me , the best way is via email ***