Harassed for someone else's debt

This is quite the strange one.. Recently I was called by this company regarding money I apparently owe Vodacom as well as Russells. The consultant read back an ID number, and I advised her that it is similar to my ID, but it is not correct. Since then I have been receiving multiple messages and calls, which makes no sense as the person they are looking for has a different ID and surname as mine. I have now had to block their numbers as they have been harassing me non stop for someone else's debt, which is really confusing but probably an error on some users behalf.