Worst customer service I have ever experienced

So, after several calls back and forth and 3 weeks later, my query has still not been resolved... I have been promised that my line will be reactivated by several different consultants only to be told on Friday that my line can't be reactivated. This lady is a supervisor and promised me that she will see what she can do and gave me an email address to email her all the documentation. Since Friday she hasn't responded to any of my emails. I can't believe that this is how they treat a client of more than 15 years...