I'm trying to bulk hard delete Account detail childs records but I'm receiving the "UNABLE_TO_LOCK_ROW, unable to obtain exclusive access to this record: []" error message. I'm curious if the apex code logic is causing this issue.  Thank you for your time. 

public with sharing class TruceCreateEntityRequest {
    @AuraEnabled
    public static Account getAccount(Id accountId) {
        return [SELECT Name, BillingCountryCode, BillingState, BillingCity, Entity_ID__c, Won_Opportunity_Count__c FROM Account WHERE Id = :accountId];
    }
    @AuraEnabled
    public static String truceCreateEntityRequest(map<string, string> body) {
        // timestamp creation
        String salt = '4947cafc63236413eeaef625cb840679';
        Long longtime = datetime.now().getTime()/1000;
        String timestamp = String.valueOf(longtime);
        // token creation
        Blob blobstamp = Blob.valueOf(timestamp);
        String EncodedTime = EncodingUtil.base64Encode(blobstamp);
        String timerequest = salt + EncodedTime;
        Blob blobRequest = Blob.valueOf(timerequest);
        Blob md5 = Crypto.generateDigest('MD5', blobRequest);
        String token = EncodingUtil.convertToHex(md5);

        String devUrl = 'https://integrations-dev.trucesoftware.com/salesforce/organization.php';
        String prodUrl = 'https://integrations.trucesoftware.com/salesforce/organization.php';

        String sandboxQuery = 'SELECT Id, IsSandbox, Name FROM Organization LIMIT 1';
        List<sObject> databaseResults = Database.query(sandboxQuery);

        String url = prodUrl;
        if ((Boolean)databaseResults[0].get('IsSandbox')) {
            url = devUrl;
        }

        body.put('token', token);
        body.put('timestamp', timestamp);
        String request_body = JSON.serialize(body);
        String companyVal = String.valueOf(body.get('company'));
        Http http = new Http();
        HttpRequest request = new HttpRequest();
        request.setEndpoint(url);
        request.setMethod('POST');
        request.setHeader('Content-Type', 'application/json;charset=utf-8');
        request.setBody(request_body);
        HttpResponse response = new Http().send(request);
        String StrResponse = string.valueOf(response);

        if (response.getStatusCode() != 201) {
            System.debug('The status code returned was not expected: ' +
                         response.getStatusCode() + ' ' + response.getStatus());
        } else {
            System.debug(response.getBody());

            // Grab entity ID from response body
            String res = response.getBody();
            String[] org = res.split(':');
            String orgID = org[2];
            orgID = orgID.substring(0,orgID.length()-1);
            // Update company by assigning it its entityID from Database
            try {
                List<Account> accountUpdate = [SELECT Entity_ID__c FROM Account WHERE Name = :companyVal LIMIT 1];
                Account entity = accountUpdate[0];
                entity.Entity_ID__c = orgID;
                update entity;
            } catch(Exception e) {
                System.debug('An unexpected error has occurred: ' + e.getMessage());
            }
        }
        return response.getBody();
    }
}