First, whether the language center will give you a separate language cas or a combined cas (covering both language and routine categories) depends on your specific situation and is determined by the evaluation of the university. This year, the British Immigration Service (UKBA) is said to have controlled the issuance of joint ca, so the probability of getting a joint ca this year will be relatively low.
In fact, it is very easy to renew your language visa in your country after reading it. You can find the teacher who helped you at that time and ask him to help you translate some needed materials. In addition, they can also prepare the application materials with the university, and let the university give you an unconditional offer to help you with the renewal procedures. There is absolutely no need to worry.
Second, into's pre-class language and uea are two institutions, so you can't quit the regular class with a deposit. Last year, UEA stipulated that the application should be made four weeks before the start of the course, deducting the deposit fee of 500 pounds. When the application was made within four weeks, it was 1000 pounds. Look at the examination time of your language course this year. Actually, it is not recommended to pay the deposit so early. Because ordinary universities won't disqualify you just because you haven't paid the deposit, even if you do, there will be an email reminder.
Also, you can see if you can sign up for a shorter language class in IELTS this time, so that the school can refund the difference to you.
I hope this helps.