Line cut while open query

There is a billing query on our lines open from December 2014. I asked to split the lines until the query is completed so that we can pay the voice lines which we use in the business. MTN IS NEVER COMING BANK TO US REGARDING ANYTHING. We would like to conclude and come to an agreement. But all that MTN does is avoid the problem. Then cut our lines! WE ARE HIGHLY UPSET AT MTN AND THE WAY OF NOT RESOLVING AN ISSUE AT HAND.