Can I upgrade my plan to Plus Edition with additional cost of £10.80 amount of is advertised at a price of £41/year, System is quoting me a total of £302.46

I recently purchased the Quickbooks Essentials Edition a few days ago at a discounted price of GBP £30.20/year.I now find myself in need of upgrading to the Plus Edition due to requirements for managing stock and purchase orders. 
Upon attempting to upgrade my subscription through the subscription and billing options in my account, I encountered a discrepancy in the pricing. The Plus Edition is advertised at a price of £41/year, which would mean an additional cost of £10.80 compared to the Essentials Edition.

However, when I proceeded to upgrade, the system is quoting me a total of £302.46 (+ £60.49 tax), which seems significantly higher than the expected difference in price. As per my calculations, the difference amount should be £10.80. I kindly request your urgent assistance in resolving this matter.