I'm about to sue.

I've lost my patience with this company. I've tried calling multiple times and I've tried live chat. I had my hotspot turned off before I even went to get it cancelled and it has not been turned on since. I cancelled it and paid my final bill of $180 in store (after confirming with the store manager that it's all I owe) and was sent a bill for $260. If they send this bill over to collections to ruin my credit score that I've been working hard to keep up this past year I will sue. Not to mention the last time I called the agent was extremely rude to me and kept me on hold for an hour before ending the call; all because I only had the account number and not the phone number for my hotspot.