We worked for almost a month: an audit was conducted, a semantic core was gathered, a website structure was developed, 5 on-page tasks were prepared for the copywriter, a competitor analysis was carried out, and a promotion strategy was formulated. At all these stages, the client was satisfied: he received materials, made clarifications, and asked to recalculate the forecast based on his data from GA - I did this without additional payment.
The conflict arose only when the actual annual budget for promoting a large online store (content + technical work + link building) was calculated. Judging by subsequent messages, the client expected a significantly lower budget, and it was after this that the narrative about "incorrectly defined organic traffic" and "minus 30%" began to appear, which were not in my documents. This means that the claims were not about the quality of the work performed, but rather that the actual cost of SEO turned out to be higher than his expectations.
The comments regarding "unprofessionalism" came only after the final estimate, while throughout the entire month of work there were no remarks about the audit, structure, or semantics. It is worth noting separately that when the platform's arbitration asked the client to provide a reasoned refusal with specific points, he took a long time to respond, even though he was online. This means he was not in a hurry to resolve the situation substantively.
Recommendation to other performers: before starting with this client, immediately fix in the project that the final forecast and budget may not match his personal expectations. In case of discrepancies in the numbers, he may question the already completed scope of work.