changing wasn’t an issue, very easily handled. And it’s all the same gas in the same pipes, just a different billing operation (and price)
Getting my accrued credit back out of my previous supplier (First Utility, FWIW) was a different matter. Took months of phone calls, misinformation, finally resolved with a cheque a week or so back.
Next (minor) gripe with my new supplier is that they are using past usage to calculate my monthly payments – but I had a new efficient boiler installed earlier in the year which by my reckoning based on month to month usage comparisons is 40% more efficient. But they want me to continue to pay for an estimated usage based on past history, hence I’m building up another large credit balance over these warmer months July -> Oct that won’t get all used up in the cold months any more because I’m using 40% less. Which at a rough count means they’ll be holding about £250 of my money for me until they can ‘review’ usage and correct.
Seems to be the business model, was practically admitted by the guy at F-U, that they want to hold your money as long as possible, I assume they invest it in future gas deals or something.