Credit Negotiation ****

So I was contacted by a sales person from this company asvised that they can help me with my credit profile and remove the red flags with a once off fee of R680. Later on the day I went through the attached sent to me to sign the I realized that no, I am not signing anything because it seems like I will be adding more to what is already due. The following day I wrote to them and advised that no, I am not accepting any of your products as I went through the attached sent. I will not be signing anything with you them. On the third days, same was not canceled instead I received an email from their team leader Phungo who tried to convince me that their product is worth signing up for. I advised him that they must not continue with anything as I did not sign anything and the POA attached forms. He then advised me that they will add an additional fee of 750 of cancelation. What cancelation fee?? Where did I sign. Now he sent an email advasing that additional fee of 350 is for cancelation. We did not ask for this people to call us and like everyone else they are very much aware that people want to fix their credit. I fail to understand why are they ****ming people in the name of the fixing their credit.