The GBP in your account sits with an FCA regulated UK bank and is therefore protected by the Financial Services Compensation Scheme (FSCS) as well as the usual bank-grade security that you would expect from a regulated bank. FSCSis the governmentscheme used to protect money in high street banks. More more information on FSCS, please refer to the official website: https://www.fscs.org.uk/.
The Wollo in your account is listed on the blockchain. The only way you will lose it is if you lose your 12 word recovery phrase or give this to someone else. Remember to keep your 12 word recovery phrase key safe.