constant junk sms messages from vodacom

For seven months i have been receiving message about data usage on my phone which is up to 18 times a day. some of the messages show cell phone numbers and they are not my numbers. They state that my data package is depleted however vodacom confirms that my data is fine (over 500MB available). numerous calls. emails and chats with vodacom customer service with reference numbers has not resolved the problem and they simply close out the ticket without doing anything. for the last five times i have complained they do not even give me a reference number. they report that it is fixed and then i receive the next message ten minutes later. i have asked for their escalation process but they will not allow me to talk to anybody only the customer service desk.