If i understood you right, issue is that during "renew process" it adds "period" to date each time you update your listings?
Renew is supposed to renew listing plan (listing period) and not just for date updating. In other words Renew here is not to renew listing date but to renew its plan period (listing live period).
To remove period extending in renew function, try to make changes in the same place as John mentioned.
1. Open the file: /includes/classes/rlListings.class.php
2. Find the code (line ~2775):
PHP Code:
Only registered members can view the code.
3. Replace with the code:
PHP Code:
Only registered members can view the code.
but my opinion on the subject that it should be not changed like this.
Renew plan function(what we changing) is for different purposes and it works as it should.
For those who need Renew listing its better to add another button which will just renew listing date and will have no relation to listing plans and upgrade,
If you want i can post instructions here it seems pretty simple.
Only problem with that way if you want to charge users for this, in this case easier to make above mentioned change, but still think its not right solution )