My question involves labor and employment law for the state of: Pennsylvania

I'm in a lawsuit against a former employer who fired me with no cause. We're in the discovery process and have received their responses.

There is one instance in which my former employer clearly lied in his responses: he said he called to tell me he was 'switching me to an easier task' because I wasn't preforming well. However, I've gotten my phone records and there clearly is no phone call from him.

What should I do with this fact? What would 'appropriate relief' be for his lying? The case is in Pennsylvania and the code says money or imprisonment can result from lying in interrogatories.

I'd also like to use this evidence of his lying to assert that there are other things he's lying about too. For instance, he said he never spoke to previous employers and did a background check with a company but doesn't know the company's name or have any proof of the transaction. I believe he DID speak to a previous employer and DID NOT do the background check and that he is again lying in both instances.

Can I use the evidence of his lying in the 1st matter to bolster stronger discovery in the second two matters -- ie, subpaeoning his phone records to show that he DID speak to the previous employer?