<human>: Can you succinctly summarize the text in 1-3 sentences?

So my sister went well over her phone bill and I just got a statement for £1,200. Her contract is under my name and it's coming out from my account. I suspended the direct debit so the money hasn't been taken out of my account as of yet. I tried speaking to EE and they said that I have to either 1 pay them £1,200 or slowly pay off the amount over the next six months so at £200 each month and it would affect my credit score also for the next 5 years :/ Also if I go with this option my contract will get extended for another 6 months without the discounts prices etc.

Is there anything I can do since I'm 20 and can't really afford to pay them £1,200? As soon as this gets settled I'm moving her phone off my name and making her pay for it herself while she slowly pays me back.
<bot>: Sister went over her phone bill that's under my name and I can't afford to pay for it. I'm fucked.