Telkom phone batteries not available in their stores for the public

We purchased a Telkom WiFi cordless phone which works off the towers. There is a re-chargable battery which I am not able to purchase from Telkom.

Li-ion battery pack 3.7V 1500mAh Model Name: AL503048

Can Telkom please advise why they are selling items to the public and the batteries are not abailable? Tried to get hold of the pro-curement division and have not had any luck either.