Since the cable has broken twice in a short period of time,
I would look at the area where it has broken. The cable is probably rubbing against the accelerator tube or similar abrasion.
The replace, disconnect the cable at the carb end,
loosen the two 17 mm pedal assembly bolts 1/4" - 3/8"
this allows the accelerator cable "S" end (that goes into the hole on the pedal arm) to be wiggled out clearing and the chassis tunnel.
Check the front of the cable tunnel and the engine end of the tube for any rough edges.
Be sure that the replacement cable has the same shaped "S" end or bend the new one to shape being careful not to weaken the "S" end.
Reinstall the cable reversing the above steps first coating the replacment cable with grease. You don't have to grease the first
12" of the cable, this will be shorted before you connect it to the carb linkage(s) due to the chassis length being less that the stock VW pan .