In an ad added to okidoki, you cannot replace one product with another, even if they are similar to each other. The ad should always contain only what was there in the first place.
Ads that do not comply with these rules are rejected. To make your ad appear again, you need to fix it.
If you do not correct the ad and return the description of the originally added product, okidoki will consider the product listed in it to be already posted on the site. Even if the ad is among the rejected ones.