Smartie?

You got it? -- that's only a matter between you and company A, nothing to do with company B, so company B (or anybody) can suggest you a promotion (so long as they don't need to pay for the cost of doing that).

Company B only needs to concern whether they are happy with company A (which is represented by you there), and if B is not happy, they are fully entitled to discontinue the business with A (and it's a matter between you and A whether A continues with you).