Worst service ever

Worst service by far! I've been a loyal customer for over 10 years and pay my bills on time. They were charging me for almost 2 years for a contract that had expired, I was promised a callback and 3 weeks later, no call.

Today I called and spoke to 5 agents under 1 hour. I had to explain myself 5 times and verify 5 times. The 5th agent told me that she would call back as she had to switch desks, that was at 16:38, it's now 17:06 and still no call back. I tried calling back and low and behold, their call center closes at 5. I am beyond livid because I wasted so much of my time for such pathetic service. Seems that this always happens when money is owed to you, same issue happened 4 years ago but now I've just lost all faith for this company.