Sometimes Amazon will offer a discount that is not generated by the seller or manufacturer. When Amazon does this it is part of a program called “Discounts Funded by Amazon.”
To remove the offer from the listing each seller need to request that the offer be removed via seller support.
Here is an example of text to use:
We request that on ASIN XXXX the Discounts Funded By Amazon program offer be removed as it interferes with previous legal agreements we have with the brand owner.
For more information on this program, you can find out more in the help sections in Seller Central here.