c) Any amendment or variation to the Conditions must be in writing and signed by us and you in the same manner as this document (or as otherwise agreed by us in writing from time to time).
c) Rhaid i unrhyw ddiwygiad neu amrywiad i’r Amodau hyn fod yn ysgrifenedig a chael ei lofnodi gennym ni a chennych chi, yn yr un modd â’r llythyr hwn.