I had a Citroen BX which wouldn't go into gear. It turned out to be that a small L-shaped piece of metal, which formed a linkage to the clutch cable, had become 'torn', so that what should have been a 90 degree angle between its two arms was more like 120 degrees.
A few blows from a mechanic's hammer knocked it back into shape and a quick bit welding ensured that it would stay there. The whole job only took a few minutes labour, with no parts to pay for, so you might find that your car can be fixed just as simply.
(Unfortunately though, the garage only spotted the warped linkage on my car after they'd already charged me for a replacement clutch, which I didn't actually need, and for 8½ hour's labour!)