401k — employer never withheld after confirmation for 7 months

401k —– in may i sent an email confirming I wanted to participate in 401k. Company has a 5% match. They confirmed stating they would implement next pay period. The 401k fund representative set up my 401k account and I decided to contribute 25% of every paycheck to the account (roughly 500.00 every two weeks.) Checked on Wednesday (7 months between events) and discovered the balance to be zero. Contacted accounting and they stated "we were going to implement in July at one year mark and accidentally forgot, my apologies, we will implement next pay period." (My one year was actually in june) I checked employee handbook and employee explanation of benifits, both state eligible after 60 days of employment.

Questions —— am I going to have to eat this loss with my 401k? —– if not what can I do? —— please talk to my like I'm stupid regarding 401k's because honestly, I am. 🙁