Vodacom giving other people's numbers to new clients!

I took out a new data sim contract about a week ago. Made the purchase online on Vodacom website. When asked do I want to keep my old number or get a new one, I chose new one. Last night and this morning I received sms's from lawyer firms about an arears account. Phoned them this morning and the guy told me it's not me they looking for and he will delete my number from the database. Few hours later I install Whatsapp on my phone for the first time using this new contract sim number and there under blocked contacts are 4 numbers with profile pics that I have never seen! Phoned Vodacom and the lady told me that they no longer give out new numbers, but give out recycled numbers to new customers. So we end up getting contacted by people looking for other people that used to own this NEW number. I am totally shocked!!