Dischem Voucher discount appearing then disappearing

Sometime ago eBucks changed their policy on voucher discounts. Previously vouchers would be discounted for an indeterminate period. This was changed to any particular voucher being discounted from the first of the month to the end of that month. This change was prominently stated on the eBucks site. And it can clearly be seen that for most vouchers this is how things have been operating. However this month Dischem vouchers were shown as discounted for the first couple of days of the month, then the discount mysteriously disappeared. eBucks have not advertised a change in the policy and their customer support has no interest in investigating the matter to provide an answer as to why Dischem is suddenly an exception to the rule which has otherwise been in place and is still be put into practice for all other vouchers.