Party 1 offers to pay for entirety of directly relevant bills if Party 2 carries out the service and which the bills pertain to. After Party 2 completes their obligation in the agreement, Party 1 decides to pay Party 2 an amount seemingly coming from no where (also only ~6%) of the directly relevant bills) Party 2 is furious and returns a portion back since it wasn’t the amount agreed to but kept half to pay for some of the bills that required immediate payment. Based on these facts (vague, I know) could Party 1 be liable for the remaining amount promised initially when stated that they would pay for all that of the relevant bills?
Unfortunately, you won't be able to get a good answer to this. When you admittedly have vauge facts, its not possible to answer, especially with contracts.
If you have a written contract, you need to have that reviewed by an attorney. No attorney will give a confident answer on a contract without reading it.
But the enforceability of a contract is based on the contract itself...not what happens after by the parties.
Hard to say, given that contracts analyses are closely tailored to the specific terms of the agreement in question, especially when that agreement is in writing. One small fact or phrase could take the analysis into an entirely different direction. As Attorney Love alluded to in his answer, the best way to obtain a lawyer's precisely correct response is to share with him/her a copy of the contract if it is in writing. If this was entirely verbal, corroborating the material terms could be a problem if the two sides disagree about that to which they agreed. Best wishes to you.
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