Disappointed Long term client - Daylight *******

My contract expired in July last year, i have been with Vodacom on contract for over 10 years and i only upgrade and renew my contract when i require a new device which is often between Jan and March the following year. This time around Vodacom has been harassing me to renew another 2 year contract threating me with higher fees for refusing to sign up for another 2 years. i have always gone on a month to month at no extra charge however this time around i am being told if i don't sign up for another 24 months they will continuously increase the charges on my account making being on month on month no longer feesable. SERIOUSLY Vodacom??? Now we enforce higher billing to force clients into renewing contracts. In all my years with Vodacom i have never heard of this but you insist on telling me you have always operated your business in this way. it is ridiculous and daylight ******* especially in todays economy.