When did you apply for your license? I only paid about £45 for mine.
Also, important to note, for those who don't know, that the UK license replaces your SA one permanently, i.e. you send it off with your passport, application and postal order, and they send back your passport and new UK license only. Haven't been asked for my license when driving back in SA, but sure it'll be an interesting conversation with the Metro when I whip out a UK license instead of a Saffer one.
And can second the frustration with opening a bank account: eventually got lucky at Lloyd's - literally the last high street bank I tried. Even had to make an appointment at HSBC only to be told they don't open accounts at the branch they sent me to. You guys using Monzo are extremely lucky.