Only the written contract matters. This deal happens all the time: someone presents a written contract to someone else, and also makes verbal promises that either alter or contradict the contract, e.g. "We won't hold you to that".
It's well understood in contract law what happens next: Only the contract matters. And typically, contracts have a clause (section) to remind you of this:
Entire Agreement: This written contract constitutes the entire agreement between parties. It overrides any prior contracts, agreements, promises, or assurances, except subsequent agreements, which must be made in writing.
So if they're promising something that contradicts or just isn't included in the written contract, they are lying. "Lying" seems like a strong word, but if they're signing the contract, they ought to be reading their own contract, and they know, or reasonably ought to know that the clause is there.
This is your cue to walk away.
If you want to be smart/clever, you can fire up Microsoft Word, type the whole contract in and format it their way, and then add additional clauses which cover the verbal promises they are giving you. Sign that version and give it back to them, and tell them that you modified it. What happens next will be your final warning about doing business with them: they'll either read it and
- go "Oh, I see you modified it, let me compare to our original... yeah that's fine" (good)
- sign it without looking (bad), or
- get angry at you for doing that (bad).
Fact is, a contract is simply an agreement between two consenting adults, even if one of those adults is richer than the other, or a corporation. The guy who writes it generally writes it to protect himself, that's just obvious. Though they try not to make it too burdensome to avoid scandal and to get people to actually sign it. But you have every right to stick up your dukes and negotiate a contract that works for you too.
Honestly if you want to do a complex rewrite of a stock contract like the one Netflix makes their customers sign, Netflix is probably going to say "we don't need your $10/month that bad".
But for larger matters, absolutely. Be bold about negotiating. Worst they can say is "no".