Simple Ira - Employer Making Me Responsible For Matching Portion. Illegal?

Hello all, this is a bit of an odd situation and I could really use some input.

My bosses made me sign an addendum to our contract when switching from 401K to a SIMPLE IRA that is stated as follows:

1. Voluntary Contributions by (PROFESSIONAL TITLE)

The (PROFESSIONAL TITLE) agrees to voluntarily contribute an amount equivalent to the matching contribution provide under the SIMPLE IRA plan, which is currently set at 3% of their eligible compensation.

1. Method and Timing of Contributions

The (PROFESSIONAL TITLE) shall fund this voluntary contribution separately and addition to any regular employee contributions. Contributions shall be made in accordance with the timelines and procedures established for the SIMPLE IRA plan

1. Acknowledgement

The (PROFESSIONAL TITLE) acknowledges that their decision to fund an amount equivalent to the matching contribution is entirely voluntary and is not a condition of their employment.

Basically, they are refusing to match 3%, which is required by the SIMPLE IRA plan, because they say I make too much and should be excluded.

Can they do this?