Phone bill

Hi Ladies.
I’m just after some advice as where to go from here, a few years ago I had a issue with a phone company. Our bills started to become $500 a month and we tried to come to an agreement to make it cheaper but it never did. It was a huge hassle with constant argument for months. Obviously my phone got cut off as I struggled to pay, the next new bill I received come to over $2K, stumped and confused I was on the phone to them trying to find answers as to why, and nothing was resolved and I was basically told I had no other option but to pay it. Next thing I know, I’ve received another bill for the amount of $7,000! I was up to wits end that I just ignored it because it felt like a battle I wasn’t going to win. It’s been a few years now and my personal information has now been handed over to a debt company who is asking I pay the amount in full. I don’t even know where to begin. I don’t even have that amount of money nor do I earn enough. Can anyone give me suggestions as to where I can settle this? I don’t even know how they got such a figure of that amount! I was on an unlimited plan. Please no judgment, I’m only after advice. I need this gone! Thank you.