Which gearbox fits my Audi A4 cabrio

[IHK 11]

Hi ive got a 2004 Audi A4 1.8t cabrio and i need a new gearbox. Ive already bought one off ebsy but it doesnt fit. I was assured it would fit. It does have a different gearbox code tho. Ive found out by reading the sticker in the boot and the sticker in my service book shich is identical that my gearbox code is HFD and my engine code is BFB. Ive seen a lot of gearboxes for sale with these 2 codes. Will any gearbox with the same 2 codes fit my car? I dont want to buy another gearbox that doesnt fit. Any help would be really appreciated. Thanks from Ian.