One sided increase in tariff

This is the clause Vodacom alludes to.<br> What is the anniversary date - is it yearly since inception of the contract, or is it after 24 months.<br> Either way, according to this clause it may seem that Vodacom is in the wrong. I am no legal eagle,<br> but according to this, anniversary date can not be two months, or 18 months into your contract. <br> <br> Any legal eagle with advice regarding this clause?<br> <br> 6. ADJUSTMENT OF CHARGES <br> 6.1 Notwithstanding anything to the contrary herein contained, Vodacom shall have the right, on each anniversary of the effective date of a Service Schedule, by written notice to the Customer, to vary the charges and fees payable by the Customer thereunder, on 1 (one) month's notice to the Customer, provided that:<br> <br> <br>