Blockchain lost funds!

I am pretty much a novice with regards most things in the crypto world but I had some funds in Blockchain and was trying to transfer to a mates wallet and it kept saying invalid address.. I don’t think blockchain allows transfers to say Cake wallet or others..

I saw some dude say he transferred to his EXCHANGE account then he could transfer out to another wallet so I thought I’d give it a go.. so clicked Send, then clicked exchange wallet and I just clicked Max funds (was only £50 But still).. it took the money and said transfer complete but now I have no idea where that money has gone!

Looking deeper into it, a normal wallet and an exchange account are two separate things and I’ve never set up an exchange account and blockchain won’t allow me to set one up!

Give it to me straight, have I lost that money forever? I’ve raised cases with blockchain but nobody responded for a couple of days and hoping one of you guys will know what’s up and how I can find my funds?

Cheers!