Most frustrating call centre i have ever dealt wit

Ever since our account was moved from Nashua Mobile to MTN we have had endless issues ... every month without fail the account is suspended due to bill limits on the account, which I keep increasing but no one seems to actually put into place! Every time I call I sit on hold for over an hour, listening to the same 30 second clip of music that is constantly repeated .. and every time someone answers the phone, I'm told I've come through to the wrong department and I am put on hold again! It is so frustrating!!! I cannot wait for our contract to be up so I can switch networks and not have to deal with this every month.