Hi lzmcivor,

It's likely that a promotional discount offer has expired and you are now being billed at the normal subscription rate, the current price of QuickBooks Online Plus is £30 + 20% VAT. 

All subscription details will show on your latest billing invoice which can be viewed by going to the Cog > Account & settings > Billing & subscriptions - please get back to us below if you have any Q's on this. 

Thanks!