No expiry date given on advert

<p>Telkom's exclusive offer! Get 500MB for ONLY R12.50. Reply 'YES' now to get this limited offer. You have until 23/10/2016 to respond. Ts & Cs apply. - This is Telkoms advert, however after replying yes I get messages that it expires on the 27th of this month! Misleading advert! Ts & Cs should rather read limited to one week only! Don't sell 500MB at a discount price if you don't disclose the time frame it is ****************! </p>