Xbox live gold giving £5 or £10 codes

It's done at random. There's no way to know why one account gets one and another doesn't.

Hello Oliver,

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Thank you for clafiying it.

Since you also haven't got a credit card, your only option for gold when you have the money is to buy a prepaid gold card, which has a 5 by 5 digit code, you scratch off the panel and type the code on either xbox.com or on the xbox itself, and that will
give you so many months of xbox live gold.

yes, like 5 times, it takes the windows live id, and password, then says welcome on the loading screen, loads about 10-20% and gives the error code