#edit sorry, posting issues.
I was going to suggest
@DX24 gets some financial advice from one of the debt counseling services. Your situation is pretty normal. Too many people don't understand finances, personal or business.
There is nothing wrong with personal debt either; providing you proactively manage it and ensure you have ways to service it through regular income/salary or selling assets. It should also be viewed as a risk which needs to be managed incase circumstances change.
I am however struggling to understand how you don't have comprehension of the charges when these are usually clearly set out in the statements or even a simple phone call to the card issuer would suffice.
It looks like the Apr may have increased to ~29% or it in the absence of clarity, it could be the £200 includes repayment proportion and interest. Again all is explained in the statement.
Credit isn't renewed, it may be reviewed and your terms changed but with a credit card it's a rolling loan/debt.
Rather than a 0% card, I would recommend a bank loan. I only suggest this as your financial acumen and discipline suggests to me that managing repayment is better with a fixed goal/loan and off credit cards where you could keep spending.
Thus, get a bank loan over 36-48months to pay off the balance and assuming your credit record is ok your bank should lend at a low apr. Cancel your credit cards and where you can, make loan overpayments. You may pay more in interest than on a 0% Apr balance transfer but it feels like a better managed lifestyle option.