My experience was different.
Videocon doesn't allow to drop pack in between (even though 30 days lock in period is over).
If you don't wish to 'continue with offer/pack after 30 days' then call customer care before 30 days lock in period is completed & instruct them to drop offer/pack automatically on 30th day. Pl. get verbal confirmation that pack will be dropped automatically on 30th day without any further calling.
If you call customer care after 30 days then it is not useful because offer/pack is automatically renewed for another 30 days at prevailing prices.
Videocon doesn't allow to drop pack in between (even though first 30 days lock in period is over). In Tatasky it is possible to drop pack after 30 days lock in period is over.